On Monday, the head of Iran's judiciary, Ayatollah Mahmoud Hashemi Shahrudi, said he hopes the deal will benefit Islam and the sovereignty of Iraq.

The agreement comes six weeks before the current U.N. mandate is set to expire. It also follows the transfer to Iraq of security responsibilities in many of its provinces as violence declined sharply over the past year.

The deal would give Iraq authority over U.S. military operations for the first time, requiring the U.S. military to ask permission to search homes, and banning American use of Iraqi territory to launch attacks on third countries.

It also would give Iraq some judicial oversight of serious crimes committed by U.S. soldiers while off-base and off-duty.